Dear Editor,The transcription activator-like effector nucleases （TALENs） and clustered regularly interspaced short palindromic repeats （CRISPR）/Cas9 genome editing systems have greatly improved the efficiency for ...
详细信息
Dear Editor,
The transcription activator-like effector nucleases （TALENs） and clustered regularly interspaced short palindromic repeats （CRISPR）/Cas9 genome editing systems have greatly improved the efficiency for generating targeted mutations in various organisms including plants （Li et al., 2012; Cong et al., 2013; Li et al., 2013; Feng et al., 2014; Ma et al., 2015b; Zhang et al., 2014, 2015）. In some plant species, the majority of mutations induced by TALENs and CRISPR/Cas9 systems are in uniform biallelic and heterozygous status in the first transgenic generation, although in some other plant species, chimeric mutations （with three or more allelic edited events within a single individual） may frequently occur （Li et al., 2013; Feng et al., 2014; Zhang et al., 2014, 2015; Ma et al., 2015b）. In many cases, it is necessary to determine the mutated sequences of the targeted alleles. However, direct sequencing （with the Sanger method） of PCR amplicons containing such biallelic or heterozygous mutations results in superimposed sequencing peaks starting from the mutation sites. Therefore, cloning of the mutation- containing amplicons and sequencing of multiple clones for each target editing site are required to determine the mutated sequences of the targeted alleles, which is tedious, time consuming, and expensive. Aimed at this problem, we have recently developed a highly reliable Degenerate Sequence De- coding （DSD） method （Ma et al., 2015a） and applied it to decode hundreds of targeted mutation events in rice and Arabidopsis （Ma et al., 2015b）. The DSD method decodes superimposed sequencing chromatograms in the following steps： （1） starting from the first overlapping-peak position on the chromatogram, manually generate a short degenerate sequence （DS） that is adjacent to the anchor sequence （AS）, which sits upstream of the first overlapping-peak; （2） query the DS against the intact reference sequence twice with a sequence analysis program to find the matched seque
Dear Editor,Dosage compensation of the male X-chromosomal genes in Drosophila results from acetylation of histone H4 Lysl6 (H4KI6) along the male X-chromosome by the MSL (male-specific lethal) complex [1].The MSL comp...
详细信息
Dear Editor,Dosage compensation of the male X-chromosomal genes in Drosophila results from acetylation of histone H4 Lysl6 (H4KI6) along the male X-chromosome by the MSL (male-specific lethal) complex [1].The MSL complex comprises five proteins (MSLI,MSL2,MSL3,MLE and MOF),as well as two non-coding RNAs (roX1 and roX2).The enzymatic activity of histone acetyltransferase (HAT) MOF (males-absent on the first) is tightly regulated by MSL1 and MSL3 [2-4].MSLI tethers MOF with the regulatory factor,the MRG domain of MSL3,through two adjacent regions at its C-terminus [4,5].Only in complex with MSL1 and MSL3,MOF is capable of specifically acetylating nucleosomal H4K16 [4,5].
暂无评论